Read the following passage and answer the question that follows.

No man knows how bad he is till he has tried very hard to be good. A silly idea is
current that good people do not know what temptation means. This is an obvious lie.
Only those who try to resist temptation know how strong it is. After all, you find out the
strength of the German army by fighting against it, not by giving in. You find out the
strength of a wind by trying to walk against it, not by lying down. A man who gives in to
temptation after five minutes simply does not know what it would have been like an
hour later. That is why bad people, in one sense, know very little about badness — they
have lived a sheltered life by always giving in.

Which of the following options can be BEST concluded from the passage?

The essence of the passage is that only someone who acts good knows how hard it can be to tempt evil. A person who does evil has already given in and hence does not know how much more he would have had to face the hardships. A good man, on the other hand, is still putting up the fight and hence knows the extent of the hardships he would have to face. 

The question asks for what bet can be concluded. Let's take a look at each option individually:

Option A: The idea of judging ourselves is not present. Further, the idea is not that to know anything, we must apply ourselves to it; the idea of resisting temptation can not be connected to this in a sensible manner. 

Option B: This is also fetched from the text's central idea, It is not about the labels of good or bad or who gets to call themselves good, but about what it means to know the temptations of falling to the other side. 

Option C: This is the best of the given options, essentially carrying a higher meaning that is present in the text. An idea similar to "having principles is easy until they are tested". The text is about how anyone can give in to temptations and stop being good, and they might never even face the real hard temptations. Only a good person can claim to have known temptation since he has been through it all. Hence, unless you have tested your belief of being good, you can not tell your true beliefs. You might think you are good, but if you falter at the slightest inconvenience, your beliefs might be unjustified. 

Option D: This is an easy elimination. Nowhere is it implied that most people are not good, so this can be concluded. 

Option E: This essentially repeats what the passage wants to say but in the reverse order. It is not that knowing temptations makes you a good person, but a good person knows what temptation is. 

Therefore, Option C is the correct answer.